In the field of botany, the radicle refers to the initial component of a seedling, (a developing plant embryo) to originate from the seed at the time of the germination process. The radicle is the embryonic root of the plant and develops downward in the soil.
It is the initial thing to arise from a seed and down into the ground to permit the seed to take up water and conduct it to its leaves so that the process of photosynthesis can start. The radicle originates from a seed via the micropyle.